It's common for city zoning codes to require developers to provide a certain number of off-street parking spaces, but some cities are starting to experiment with allowing developers to substitute other mobility choices for parking.

Planners typically don't like off-street parking requirements, as we explained in our post on Parking Benefit Districts, because they work against compact walkable development, increase housing costs, and induce more driving. But they tend to be popular with homeowners, as a way of reducing competition for limited curb parking spaces.

At the Congress for New Urbanism in Detroit last month, a session on 'Missing Middle' housing types featured a discussion about one alternative approach that's been gaining in popularity recently: letting developers swap in car share pods, transit passes, bike share passes, or bike parking, to receive credit toward the number of car parking spaces required by zoning.

Jason Laub of Nautilus Group discussed the GreenTRIP certification system developed by TransForm, which provides a framework for these kinds of swaps for developers and city officials, and a rating system similar to LEED for recognizing high-achieving projects.

Laub pointed to several examples of projects around the country where developers were able to save significant sums of money by providing a range of transportation benefits to tenants instead of parking garages. A single garage parking space can cost between $20-30,000, or more if it's underground, and most of the alternatives can be quite a bit cheaper, depending on the local circumstances.

Garden Village, a project built by Nautilus in Berkeley, California was the first to receive a Platinum rating from GreenTRIP. The developer had initially wanted to construct a building with 77 apartment units and 49 parking spaces in an underground parking garage, but the $2.3 million price tag for the garage would have required them to price the units higher than they wanted.

But using the GreenTRIP system, they were able to save $1 million and price the units more affordably by eschewing the parking and spending just $1.23 million on a suite of other mobility options. These included two discounted transit passes per unit for 40 years, an on-site car-sharing service with 4 cars, 220 bike parking spaces with bike hooks in the units, one grocery cart per unit, and more.

Laub framed this as an issue of increasing the range of housing choices in neighborhoods to include options between single-family homes and larger apartment houses. Parking politics is one of the more important checks on those middle options, so finding creative ways to neutralize that issue is a key piece of increasing walkable urban downtowns and neighborhoods.